A fuel gas supply system has been suggested, which includes control means for adjusting an amount of fuel gas supplied to a load apparatus such as a gas turbine so as to maintain a discharge pressure of a compressor which compresses the fuel gas within a set range.
However, in the fuel gas supply system of the related art, in some cases, it is not possible to appropriately cope with rapid variation of consumption in the fuel gas which is generated during interruption of a load, during tripping of a gas turbine, or the like. Accordingly, a technology has been suggested, which maintains a discharge pressure of a compressor at a set value by controlling an opening degree of an inlet guide vane (IGV) provided in the compressor, and returns a portion of the fuel gas discharged from the compressor to an inlet side of the compressor by rapidly opening an anti-surge valve (ASV) (also referred to as a recycle control valve (RCV)) which is connected to an outlet of the compressor during interruption of the compressor or the like so as to avoid so-called surging.
In addition, a fuel gas supply system has been suggested, which further improves the above-described fuel gas supply system, and can obtain improved control results not only during normal operation but also during interruption of the load, tripping of the compressor and the gas turbine, or the like, by using not only the inlet guide vane but also the anti-surge valve so as to control the discharge pressure of the compressor (for example, refer to PTL 1).